A conventional long wavelength infrared (LWIR) detector or image sensor may be used for detection of a target in battlefield conditions, where smoke or debris may otherwise inhibit detection of the target. However, when battlefield conditions do not inhibit detection of a target, a conventional medium wavelength infrared (MWIR) detector or image sensor may be used to provide better resolution capability than a LWIR detector or image sensor, especially for long range target identification. To achieve LWIR and MWIR detection capabilities, a dual band detector or image sensor is required.
A dual band detector may be achieved using a two-color focal plane array, rather than a mono-color focal plane array that is typically used in a conventional LWIR detector and in a conventional MWIR detector. A two-color focal plane array may be manufactured to detect both an LWIR signal and an MWIR signal. However, a two-color focal plane is more difficult and costly to manufacture than a mono-color focal plane array.
Accordingly, there is a need for a dual band detector or image sensor that overcomes the problems noted above and others previously experienced for detection of a target at long range and under battlefield conditions.